1. Field of the Invention
The present invention relates to a medical instrument used in conjunction with an endoscope as well as to an endoscope system which allows various operations of medical equipment and functional operations of an endoscope to be performed easily.
2. Description of the Related Art
Recently, endoscopes have been widely used in the medical field. Generally, the endoscope includes an elongated insertion portion, a bendable bending portion located in a distal part of the insertion portion, and an operation portion equipped with knobs, switches, and the like for performing various operations of endoscope functions.
With the insertion portion inserted into a body cavity of a subject, the endoscope can be used to observe organs in the body cavity or conduct various treatments using a treatment instrument, i.e., a medical instrument, inserted into a treatment instrument channel, as required.
In the case of conventional endoscopes used for medical treatment, a surgeon inserts the treatment instrument manually into the treatment instrument channel by holding a sheath of the treatment instrument. However, the insertion of the treatment instrument, which can be as long as 2 m, not only takes time and labor, but also requires close attention. Thus, the insertion and various operations of the treatment instrument are extremely troublesome.
To solve such a problem, for example, Japanese Patent Application Laid-Open Publication No. 57-190541 discloses an endoscope which, being equipped with a treatment instrument insertion/withdrawal apparatus for use to insert and withdraw a treatment instrument into/from a treatment instrument channel of the endoscope, deactivates mechanical insertion and enables fine manual insertion operation when the treatment instrument approaches in the vicinity of a distal end of an insertion portion of the endoscope.
Also, Japanese Patent Application Laid-Open Publication No. 2000-207 discloses a treatment instrument insertion/withdrawal apparatus for an endoscope. The treatment instrument insertion/withdrawal apparatus includes means for operating a treating portion installed at a distal end of a treatment instrument in addition to a function to insert and withdraw the treatment instrument into/from a treatment instrument channel of the endoscope, and allows various operations of the treatment instrument insertion/withdrawal apparatus to be performed using a foot switch.
A surgeon who performs treatments using an endoscope and treatment instrument brings a treating portion of the treatment instrument close to an affected area in a subject and then adjusts orientation of the treating portion by grasping the sheath. In so doing, the surgeon often twists a sheath of the treatment instrument. At his time, the surgeon grips the sheath of the treatment instrument by a proximal part which is not inserted into the endoscope. Consequently, rotation caused by twisting is transmitted to a distal end where the treating portion is located. That is, torsional stresses of the sheath of the treatment instrument are transmitted to the entire sheath.